A good operator should always be clear about the type and strength of the geological formation being drilled into, and what kind of drill rods and tools to use, and what drilling method is most effective. Only in this way can the operation be well controlled, the load be reduced to the lowest, the wear be minimized, and the footage be fastest.
The rotary drilling rig can be divided into four drilling methods according to the geological conditions: cutting, crushing, stirring and grinding.
1. Cutting type
Cutting drilling uses bucket teeth, using double-bottom sand bucket with friction-type drill rods, drilling into relatively stable and low-resistance formations, generally geological strength within 400 kPa such as mud layer, silt and sand layer, by rotating bucket teeth to cut, can reduce resistance and increase drilling speed.
2. Crushing type
Crushing drilling uses cutting teeth to drill, mostly using double-bottom rock bucket, according to the geological strength can be configured with friction or lock-type drill rods, can drill into strength 500 kPa to 1000 kPa of gravel, mudstone, sandstone, shale and medium weathering, etc., by applying pressure to the alloy point on the cutting teeth to achieve crushing drilling.
3. Stirring type
Can use double-bottom sand bucket and double-bottom rock bucket, can also cooperate with Baoe teeth, due to the different types of geology, resulting in the change of drilling method, such as pebble layer, due to the irregular arrangement of pebbles, can not be cut and crushed, can use stirring type drilling, using the main reel hanging drill rods, using the bucket teeth tip to stir pebbles, after loosening the pebbles in the floating down bucket, this operation method is to avoid the strength and vibration of pebbles.
4. Grinding type
Using rock tube drill and tooth shaft drill, cooperating with lock-type drill rods to drill into rock formations calculated by single-week compressive strength, strength from several megapascals to tens of megapascals, usually for rock end bearing piles, by tube drill ring cutting grinding into rock, or by tooth shaft drill grinding drilling, at the same time according to the type, strength, brittleness and cracks of rock formation do not exclude the possibility of crushing.
Introduction of various drilling methods of rotary drilling rig
